1. Field of the Invention
This invention relates to cable tighteners and, more particularly, to power drives for these tighteners.
2. Description of the Prior Art
Turnbuckle assemblies are conventionally used for tightening load binding cables in various fields and also in the marine industry for tightening cables lashing barges to each other and to marine tugboats. Manual turnbuckles used in the marine industry require considerable manual effort and time in order to operate them to properly tighten marine lashing cables. Therefore, inasmuch as numerous lashing cables between a marine tugboat and an adjacent barge, as well as additional lashing cables between additional barges lashed together and to the first-mentioned barge, must be tightened, considerable manual effort and time may be saved through the utilization of a power drive for a cable tightener.
U.S. Pat. No. 4,830,339 to McGee et al. discloses a power drive for coupling to the ratchet wheel of a turnbuckle assembly. This power drive, however, suffers from several problems. This power drive includes a pair of laterally spaced, generally parallel opposite side members having corresponding first and second ends. The first ends define aligned inverted-U-shaped notches formed therein which open laterally outward of the side members in directions disposed generally normal to the longitudinal extent of the side members. When the power drive is engaged with the turnbuckle assembly, these notches lie over and receive the longitudinal central portion of the assembly which has an external gear wheel thereon. The power drive also includes a drive gear disposed between the side members and engageable with the gear wheel of the turnbuckle. The drive gear is connected to a hexagonal head disposed outside one of the side members. An impact wrench is operatively engageable therewith to rotate the drive gear and the engaged turnbuckle gear wheel.
Since the motive means (i.e., the impact wrench) is not permanently attached to the power drive of McGee, the drive is not efficient to use and requires the additional time necessary to find the impact wrench and engage it with the hexagonal head.
Additionally, this drive is not always safe to use. If improperly directed rotary torque is applied by the impact wrench to the hexagonal head, the power drive will be forced upwards and jump off the turnbuckle gear wheel, possibly causing damage or injury.